DE102013214012A1 - bearings - Google Patents

Abstract

A sliding bearing for an internal combustion engine comprises a metal layer (2) having an inner peripheral surface formed to extend along at least a part of a cylindrical shape and a resin coating layer (3) formed on the inner peripheral surface of the metal layer (2). The inner peripheral surface of the metal layer (2) has annular or spiral-shaped groove portions that extend in a generally circumferential direction of a cylindrical shape so that the inner peripheral surface has protruding portions that are disposed adjacent to each other in an axial direction of the cylindrical shape and which extend in the generally circumferential direction. The resin coating layer (3) is formed to match shapes of the groove portions and the protruding portions. t and Rpk satisfy the following relationships: 1.0 µm t 5.0 µm and 0.06 Rpk / t 5.04, where t is an average coating thickness of the resin coating layer (3) at positions other than the apexes of the protruding portions and Rpk is a reduced peak height of the resin coating layer (3).

Description

TECHNICAL AREA

The present invention relates to a plain bearing and in particular relates to a sliding bearing for an internal combustion engine.

BACKGROUND

A structure having a resin coating layer applied on an outer surface of a bearing alloy layer is known to be effective as a structure for improving the sliding bearing properties. A sliding bearing is proposed as an example of the above structure (see Patent Document 1: JP-A-2004-211859 ) in which a coating layer containing molybdenum disulfide (MoS ₂ ) as a solid lubricant and a PAI resin (polyamide-imide resin) as a binder resin is formed on a level surface of the bearing alloy layer. The coating layer has a spiral groove and annular protrusions formed as a sipe and supernatant shape on the surface thereof. In the plain bearing, the regular-shaped sipe and supernatant shape on the surface of the coating layer can hold lubricating oil in the sipe portions of the sipe and supernatant mold. Therefore, an improvement in seizure resistance can be expected.

The sliding bearing described in Patent Document 1 is intended to improve its conformability to a rotating shaft by plastic deformation of the coating layer (see paragraph 0006 of Patent Document 1). However, it may be difficult for the coating layer to plastically deform because the coating layer is made of a synthetic resin and has high elasticity. Therefore, it may take a long time before conformity is achieved. It can also be assumed that the wear of the coating layer achieves conformity to the rotating shaft. However, it may take a long time before adequate conformity is achieved by wear of the coating layer because the synthetic resin constituting the coating layer has a low friction property.

Examples of techniques that focus on the above problem include one in Patent Document 2: JP-A-2011-179566 described technique. In the art, the sliding bearing has a bearing alloy layer having annular grooves and peaks formed thereon, and has a coating layer made of a low friction synthetic resin covering a surface of the bearing alloy layer. The surface of the coating layer is formed as an incision and supernatant surface to match a cut and supernatant surface of the bearing alloy layer. Since the bearing alloy layer is provided with the crests as above, the crests of the bearing alloy layer are expected to plastically deform when a load from the rotating shaft is applied to the sliding bearing. The above structure is intended to accelerate the conformity of the bearing to the rotating shaft, even in a configuration using the coating layer made of a synthetic resin with low friction. In an experimental example described in Patent Document 2, the peaks of the bearing alloy layer result in plastic deformation despite the presence of the overcoating layer made of the synthetic low friction resin (see paragraphs 0012 and 2 of Patent Document 2).

However, an experimental example described in Patent Document 2 assumes a condition that the bearing contact pressure is 84 MPa (50 MPa in FIG 3 ), which is close to the limit contact pressure performance of general aluminum bearings. The experimental example assumes the experimental condition involving very high contact pressure compared with contact pressure (about 10 to 20 MPa) generated in an actual environment of use of internal combustion engines. Although the tips of the bearing alloy layer can be plastically deformed under the very high contact pressure, it is believed that the vertices of the bearing alloy layer can not be plastically deformed as intended in the actual general environment of use (contact pressure about 10 to 20 MPa) when the bearing is in the internal combustion engine is applied. Therefore, it is considered that it is difficult to achieve conformity in a short period of time in the actual general use environment.

SUMMARY

The present invention is made to solve the above problems, and an object of the present invention is to provide a sliding bearing for an internal combustion engine capable of achieving conformity in a short period of time through appropriate wear of a resin coating layer.

The inventors of the present invention have made careful studies to solve the above problem, and have come to every aspect of the present invention as follows.

That is, according to a first aspect of the present invention, a sliding bearing for an internal combustion engine comprises:
a metal layer having an inner peripheral surface formed to extend along at least a part of a cylindrical shape; and
a resin coating layer formed on the inner peripheral surface of the metal layer, wherein:
the inner peripheral surface of the metal layer has annular or spiral groove portions extending in a generally circumferential direction of the cylindrical shape so that the inner peripheral surface has protrusion portions disposed adjacent to each other in the axial direction of the cylindrical shape and extending into extend in the generally circumferential direction;
the resin coating layer is formed to conform to shapes of the groove portions and the protrusion portions; and
t and Rpk satisfy the following relationships: 1.0 μm ≤ t ≤ 5.0 μm and 0.06 ≤ Rpk / t ≤ 5.04, where t is the average coating thickness of the resin coating layer at positions other than the peaks of the protrusion areas, and
Rpk is a reduced peak height of the resin coating layer.

When the average coating thickness of the resin coating layer of the sliding bearing and the ratio of the reduced peak height to the average coating thickness are within the respective above value ranges, it is possible to suitably control the time required for the initial wear of the resin coating layer, particularly near the above Vertex of the protrusion portions of the metal layer, even in a case where the resin coating layer is made of a resin material having a low friction property. That is, in the above configuration, even in a case where the resin coating layer is made of a resin material having a low friction property, the resin coating layer is more likely to be worn near the apex of the protrusion portions of the metal layer, thereby ensuring conformity (initial conformity) within a short period of time is completed. In addition, the sliding bearing for an internal combustion engine according to the present invention can complete the conformity in a short period of time due to the proper wear of the resin coating layer even in a general environment of use other than the particular environment which causes the very high contact pressure (equal to or greater than 50 MPa), as in the experimental example described in Patent Document 2. In the above, the general use environment includes a situation where normal contact pressure (about 10 to 20 MPa) that may occur during actual use in the internal combustion engine is generated and it is unlikely that the bearing alloy layer peak covered by the resin coating layer is plastically deformed , Thus, it is possible to provide a preferable solution to the problematic situation where the sliding bearing with the resin coating layer takes a long time to achieve conformity.

Note that "completing conformity" means that a coefficient of friction of the sliding bearing on the rotating shaft reaches a saturation level from which the friction coefficient does not change greatly, e.g. B. during the observation of the change over time of the friction coefficient.

In the sense of the statement "positions different from peaks of the protrusion areas", z. For example, the positions other than peaks of the protrusion portions of the bearing alloy layer correspond to positions located outside a range of 15 μm on either side of apex positions of the protrusion portions of the bearing alloy layer in the axial direction when viewed in a cross section along the axial direction of the cylindrical one Shape.

In the present application, the internal combustion engine is not limited to an internal combustion engine used for a private automobile. The above configuration can achieve similar effects even in the case of large-diameter bearings used for internal combustion engines of ships or large vehicles such as ships. B. buses and trucks.

In addition, because of the conformity, the metal layer having a high thermal conductivity may be partially exposed and the resin coating layer having a low thermal conductivity becomes thinner. As a result, the heat distribution property of the entire sliding bearing improves, which advantageously improves the seizure resistance.

According to a second aspect of the present invention, the average coating thickness t and the reduced peak height Rpk of the resin coating layer satisfy the following relationships: 2.0 μm ≤ t ≤ 4.5 μm and 0.1 ≤ Rpk / t ≤ 2.0.

With the above configuration, it is possible to more preferably achieve a more preferable effect of attaining conformity within a short time.

According to a third aspect of the present invention,
satisfy T, t and σ of the following relationship: t - 2σ ≦ T ≦ t + 2σ, where σ is the standard deviation of the coating thickness of the resin coating layer measured at the positions other than the peaks of the protrusion regions, and
T is an actual measurement of coating thickness;
Rsma and Rsmr satisfy the following relation: | Rsma - Rsmr | ≤ 0.05 mm, wherein Rsma is an average length measured between the adjacent protrusion regions on the inner peripheral surface of the metal layer, and
Rsmr is an average length measured between corresponding adjacent protrusion portions of the resin coating layer, corresponding to the protrusion portions of the metal layer and
Rsma and Δ satisfy the following relationship: Δ ≤ Rsma / 3, wherein Δ is a distance measured in the axial direction between one of the protrusion regions on the inner peripheral surface of the metal layer and a corresponding one of the protrusion regions of the resin coating layer, the corresponding region being positioned closest to the one of the protrusion regions of the metal layer.

As above, the coating thickness of the resin coating layer is generally uniform, and the intervals and phases of the incision and supernatant shape of the metal layer and the incision and supernatant shape of the resin coating layer generally coincide, respectively. Therefore, it is possible to precisely match the surface shape of the incision and the protrusion of the resin coating layer to the surface shape of the incision and the protrusion of the metal layer, i. H. It is possible to approximate the surface shape of the resin coating layer to the surface shape of the metal layer. Due to the above, it is possible to suppress the elastic deformation of the resin coating layer, and thereby it is more likely that the resin coating layer is subjected to wear for initial conformity. As a result, the time required for conformity can be advantageously shortened.

According to a fourth aspect of the present invention, the resin coating layer has a scratch resistance in the range of 500 MPa to 2000 MPa. By using the resin coating layer having a scratch resistance within the above range of values, the occurrence of the wear for the initial conformity becomes more likely, and thereby the time required for the conformity can be advantageously shortened. Note that the scratch resistance will be described later.

According to a fifth aspect of the present invention, the resin coating layer comprises a base resin and a solid lubricant; in which
the base resin contains polyamide-imide and polyamide corresponding to 2 to 20% of the polyamide-imide by volume;
the solid lubricant contains one or more of molybdenum disulfide, tungsten disulfide, boron nitride and graphite; and
the solid lubricant corresponds to a total of 20 to 60% of the entirety of the resin coating layer by volume.

As above, by adding the polyamide (PA) corresponding to 2 to 20% by volume of the polyamide-imide (PIA) to the polyamide-imide, it is possible to properly define the expansion properties of the resin coating layer. In addition, by adding the solid lubricant to the resin coating layer so that the solid lubricant corresponds to 20 to 60% of the total resin coating layer by volume, it is possible to achieve a reduction in the coefficient of friction, thereby suppressing an increase in temperature. As a result, it is possible to suppress the occurrence of seizure phenomena.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and technical advantages of the present invention will become apparent from the following description and exemplary embodiments of the invention, taken in conjunction with the accompanying drawings, in which:

1 (A) and 1 (B) schematic enlarged views are that have a cross section of a sliding bearing according to the invention for an internal combustion engine according to an embodiment of the present invention, wherein the cross section along the axial direction of the sliding bearing is made. 1 (A) represents a state before the initial conformity of the plain bearing and 1 (B) represents a state after completion of the initial compliance;

The 2 (A) to 2 (C) 12 are schematic diagrams illustrating the relationship between a surface shape of a bearing alloy layer and a surface shape of a resin coating layer of the sliding bearing according to the embodiment. 2 (A) FIG. 10 illustrates a method for measuring a coating thickness of the resin coating layer on the surface of the bearing alloy layer. 2 B) represents the relationship between lengths measured between protrusion areas formed on the surface of the bearing alloy layer and lengths measured between protrusion areas formed on the surface of the resin coating layer. 2 (C) represents the deviation between the protrusion areas formed on the surface of the bearing alloy layer and the protrusion areas formed on the surface of the resin coating layer;

3 FIG. 13 is a table showing experimental results of initial conformity of the sliding bearing for the internal combustion engine according to several embodiments of the present invention, and further illustrating experimental results of comparative examples; FIG. and

4 FIG. 14 is a comparison diagram of the time variation of the friction coefficient of the engine sliding bearing between a case of the engine sliding bearing according to an embodiment of the present invention and a case of an engine sliding bearing of a comparative example.

PRECISE DESCRIPTION

Hereinafter, a sliding bearing for an internal combustion engine according to an embodiment of the present invention with reference to the 1 (A) and 1 (B) described.

1 (A) is a schematic view showing a partially enlarged cross section of a sliding bearing 10 in the form of a cylinder or a half cylinder according to the present embodiment, wherein the cross section along the axial direction of the sliding bearing 10 is made. As shown, the sliding bearing 10 In the present embodiment, a bearing alloy layer 2 (Metal layer) made of an aluminum alloy and having a surface of a supporting metal layer 1 pressure welded. The aluminum alloy from which the bearing alloy layer 2 preferably has a Vickers hardness equal to or greater than 30. The bearing alloy layer 2 has annular or spiral groove portions formed on an inner peripheral surface thereof, ie, a surface of the bearing alloy layer 2 opposite the support metal layer 1 , The groove portions extend in a generally circumferential direction of the cylindrical shape. As a result, the protrusions formed between the groove portions adjacent to each other in the axial direction provide annular or spiral successive protrusion portions extending in the generally circumferential direction. In addition, the surface of the bearing alloy layer is 2 covered with a resin coating layer 3 , The surface of the resin coating layer 3 has incisions and protrusions corresponding to the cuts and protrusions on the surface of the bearing alloy layer 2 are formed. Note that the aspect ratio in the drawings is different from that of the actual journal bearing and the dimension in the axial direction is compressed. Thus, the sliding bearing 10 With the above configuration, the regular groove portions formed on the surface of the resin coating layer 3 are formed. Accordingly, lubricating oil can be uniformly distributed on the inner peripheral surface of the sliding bearing 10 by feeding the lubricating oil into the groove areas. As a result, even if a rotating shaft (not shown) abuts against the inner peripheral side of the sliding bearing 10 adapted, rotated at high speed, possible, the increase in temperature of the plain bearing 10 which gives excellent seizure resistance.

In the plain bearing 10 According to the present embodiment, the average coating thickness of the resin coating layer 3 and the ratio of the reduced peak height of the resin coating layer 3 Defined in detail to the average coating thickness, to achieve conformance (ie conformance or initial conformity) of the plain bearing 10 to the rotating shaft by wear of the resin coating layer 3 (and in some cases wear of the bearing alloy layer 2 ) to accelerate.

In the plain bearing 10 According to the present embodiment, when the average coating thickness t is defined as an average value of the coating thickness of the resin coating layer 3 , measured from the vertices of the supernatant regions of the bearing alloy layer 2 different positions, the resin coating layer 3 in particular so formed that the average coating thickness t in a Range of 1.0 μm to 5.0 μm (1.0 μm ≤ t ≤ 5.0 μm). For example, as in 2 (A) represented by lines with arrows at both ends, the average coating thickness t is an average value of the coating thickness at 10 points of the resin coating layer 3 which are located at positions that are from the vertices of the protrusion areas of the bearing alloy layer 2 are different. Note that 2 (A) A diagram is that positional relationship between a surface 2a the bearing alloy layer 2 and a surface 3a the resin coating layer 3 in the cross-sectional view in 1 (A) schematically represents.

Note that in the present embodiment, the peaks of the protrusion areas of the bearing alloy layer 2 different positions correspond to positions located outside a range of 15 μm on either side of the vertex positions of the protrusion portions of the bearing alloy layer 2 in the axial direction when observed in a cross section along the axial direction. Each measurement is performed according to such a definition.

Furthermore, the sliding bearing 10 of the present embodiment is formed so that the ratio of the reduced peak height Rpk on the basis of JIS B0671-2 (ie ISO 13565-2: 1996 ) to the average coating thickness t of the resin coating layer 3 in a range of 0.06 to 5.04 (0.06 ≤ Rpk / t ≤ 5.04).

In the above configuration, parts of the resin coating layer are more likely 3 near the apices of the supernatant regions of the bearing alloy layer 2 are subjected to wear by friction with the rotating shaft during rotation of the rotating shaft. As a result, the conformity of the sliding bearing 10 and completes the rotating shaft in a short time. Note that "completing the conformity" means that the friction coefficient of the sliding bearing 10 at the rotating shaft reached a saturation level within an initial period of use of the sliding bearing 10 , z. B. while the change over time of the friction coefficient is observed. 1 (B) is a schematic view showing an example of a cross section of the sliding bearing 10 represents that completeness has completed. In the present example, in addition to the parts of the resin coating layer 3 near the apices of the supernatant regions of the bearing alloy layer 2 , the vertex portions of the protrusion portions of the bearing alloy layer 2 also worn out when the initial compliance has been completed.

After the conformity is completed, oil is easily drawn into a space between the rotating shaft and the sliding bearing, and thereby an oil film is easily moldable. As a result, a low friction coefficient can be achieved. When the resin coating layer 3 , which is highly elastically deformable, on the surface of the sliding bearing 10 remains in substantial amount and thickness, when the conformity is completed, the formed oil film may have a nonuniform thickness depending on the positions due to the elastic deformation of the resin coating layer 3 , As a result, the friction coefficient can be discontinuous and remain high. In contrast, in the plain bearing 10 According to the present embodiment, after the conformity is completed, parts of the metal surface of the bearing alloy layer 2 be exposed, leaving the inner peripheral surface of the plain bearing 10 has a mixed structure of the metal and the resin. Regarding the resin coating layer 3 remaining on the inner peripheral surface when the conformity has been completed, there remains only a thin resin coating layer 3 , As a result, it is possible to influence the elastic deformation of the resin coating layer 3 to suppress. In other words, the oil film thickness is stabilized and the friction coefficient is lowered.

As above, parts of the bearing alloy layer 2 having a high thermal conductivity, be exposed due to the conformability and the resin coating layer 3 , which has a low thermal conductivity, becomes thinner. As a result, the heat distribution property of the entire sliding bearing improves 10 and thereby the seizure resistance is improved.

In the plain bearing 10 In the present embodiment, the wear of the resin coating layer proceeds 3 gradually from the apices of the protrusion portions of the resin coating layer 3 and areas in the neighborhood of the vertices when conformity takes place. Therefore, even in a case where a part of the bearing alloy layer becomes 2 is exposed, the exposed areas gradually larger from a very narrow range. As a result, the lubricating oil always exists between the exposed bearing alloy layer 2 and the metal of the rotating shaft, and therefore, the metals do not suddenly and directly contact each other in wide areas of the metals. As a result, it is possible to effectively suppress the occurrence of seizure caused by the contact of the metals.

Based on tests performed by the inventors, it has been found that the initial conformity due to the wear can be completed within a short period of time when the value of Rpk / t is smaller than 0.06. However, such a configuration does not contribute to the reduction of the coefficient of friction and the improvement of the seizure resistance after the conformity has been achieved. On the other hand, when the value of Rpk / t is larger than 5.04, the friction coefficient can be reduced and the seizure resistance can be improved after the conformity is achieved. However, such a configuration does not accelerate initial compliance due to wear in a general application environment.

Furthermore, the average coating thickness t of the resin coating layer should be 3 preferably in a range of 2.0 μm to 4.5 μm (2.0 μm ≤ t ≤ 4.5 μm) and the ratio of the reduced peak height Rpk of the resin coating layer 3 to the average coating thickness t should preferably be in a range of 0.1 to 2.0 (0.1 ≦ Rpk / t ≦ 2.0). Thereby, it is possible to more preferably exercise the above effects.

In addition, it is preferable that the coating thickness of the resin coating layer 3 is generally uniformly formed at the vertexes of the protrusion regions of the bearing alloy layer 2 different positions. Specifically, the actual measured value T of the above coating thickness should preferably fall within the following range: t - 2σ ≦ T ≦ t + 2σ, where σ denotes the standard deviation of the measured value of the above coating thickness.

Further, it is preferable that the difference between Rsma and Rsmr is equal to or less than 0.05 mm (| Rsma-Rsmr | ≤ 0.05 mm), where Rsma is the average value of the lengths (represented by dashed lines with arrows on both Ends in 2 B ) measured between the adjacent supernatant regions of the bearing alloy layer 2 , and Rsmr denotes the average value of the lengths (represented by solid lines with arrows at both ends in FIG 2 B ) measured between adjacent supernatant regions of the resin coating layer 3 corresponding to the supernatant regions of the bearing alloy layer 2 , designated. In other words, the distance of the cut and supernatant shape of the bearing alloy layer should be 2 preferably generally equal to the pitch of the incision and supernatant form of the resin coating layer 3 ,

Further, it is preferable that the distance Δ is equal to or smaller than one-third of the average length Rsma measured between the adjacent protrusion portions of the bearing alloy layer 2 (Δ ≦ Rsma / 3), wherein the distance Δ is measured in the axial direction between a protrusion region of the bearing alloy layer 2 (eg vertex P2 in 2 (C) ) and the nearest protrusion area of the resin coating layer 3 (eg vertex P3 in 2 (C) ). In other words, it is preferable that the difference between the phase of the incision and supernatant shape of the bearing alloy layer 2 and the phase of the incision and supernatant form of the resin coating layer 3 is small.

As above, the coating thickness of the resin coating layer is 3 generally uniform and the pitches and phases of the incision and supernatant shape of the bearing alloy layer 2 and the incision and supernatant shape of the resin coating layer 3 generally agree. Thereby, it is possible to change the surface shape of the resin coating layer 3 to the surface shape of the bearing alloy layer 2 adapt (or approximate). Due to the above, it is possible to elastically deform the resin coating layer 3 to suppress and wear of the resin coating layer 3 to reinforce for the initial conformity. Accordingly, it is advantageously possible to shorten the time required to complete the conformity even in a general use environment.

Furthermore, the scratch resistance of the resin coating layer should 3 preferably falling in the range of 500 MPa to 2000 MPa. Incidentally, the scratch resistance refers to the degree of resistance when the resin coating layer 3 is scratched with a conical diamond impression body, and corresponds to the value calculated by dividing the frictional force by the protruding surface of the indentation on the resin coating layer 3 that was caused by the indentation body. Because for the coating, the resin coating layer 3 is used with the scratch resistance within the above range, it is more likely that the wear of the resin coating layer 3 for the initial conformity occurs. As a result, it is advantageously possible to shorten the time required to complete the conformity.

The resin coating layer 3 should preferably contain a base resin and a solid lubricant. The base resin should preferably contain a polyamide-imide (PAI) and a polyamide (PA) corresponding to 2 to 20% of the polyamide-imide by volume. The solid lubricant should preferably contain one or more of molybdenum disulfide, tungsten disulfide, boron nitride and graphite and total 20 to 60% of the total Resin coating layer 3 , by volume.

As above, by adding the polyamide corresponding to 2 to 20% by volume of the polyamide-imide to the polyamide-imide, the expansion properties of the resin coating layer are possible 3 to define correctly. In addition, it is by adding the solid lubricant to the resin coating layer 3 so that the solid lubricant contains 20 to 60% of the total resin coating layer 3 , in terms of volume, it is possible to further reduce the friction coefficient and suppress the increase in temperature during rotation of the rotary shaft. This makes it possible to suppress the occurrence of seizure phenomena.

3 is a table showing the results of a test performed by the inventors of the present invention for measuring the friction coefficient stabilizing time and the final friction coefficient as indices showing the conformability of the sliding bearing 10 indicate under different conditions.

Samples of the plain bearing used in the present test 10 are made as follows. First, the aluminum alloy bearing alloy layer becomes 2 with the support metal layer 1 pressure welded and the resulting workpiece is processed into a semi-cylindrical shape. The inner surfaces of the samples in the form of half cylinders are machined with different degrees of roughness. Subsequently, a spraying method is used to form a layer containing a resin as a main component and the resin coating layer 3 corresponds, with different coating thicknesses. Subsequently, the workpiece is fired at 200 ° C for about 1 hour to obtain the test sample.

Thus, as in 3 shown various samples (first to thirteenth embodiment examples (A-1 to A-13) and first to fourth comparative examples (B-1 to B-4)), with various settings of components and coating thicknesses of the resin coating layer 3 and various types of basic surface roughness.

The temporal change of the friction coefficient is measured as a test object.

Specific conditions for the test are as follows.
Test duration: 6 hours
Test-specific load: 10 MPa
Rotation speed: 1300 rpm
Feed oil temperature: normal temperature
Wave: Taken S45C
Lubricant: 5W-30
Bearing size: Outer diameter 56 mm, width 18 mm, thickness 1.5 mm

The table in 3 shows the first to thirteenth embodiment examples (A-1 to A-13) as examples in which the average coating thickness t of the resin coating layer 3 is in a range of 1.0 μm to 5.0 μm (1.0 μm ≤ t ≤ 5.0 μm) and the ratio of the reduced peak height Rpk to the average coating thickness t is in a range of 0.06 to 5.04 is (0.06 ≤ Rpk / t ≤ 5.04). When the average coating thickness t is equal to or larger than 1.0 μm, the resin coating layer may 3 slightly uniform in thickness on the bearing alloy layer 2 be formed.

Also shown are the first to fourth comparative examples (B-1 to B-4) in which at least one of the average coating thickness t and the ratio of the reduced peak height Rpk to the average coating thickness t is outside the above ranges.

The time required for stabilizing the friction coefficient (friction coefficient stabilizing time) is measured as an index of the time required to complete the conformity for the respective embodiment examples and comparative examples. In addition, the resulting friction coefficients (final friction coefficients) are measured for the respective embodiment examples and comparative examples.

For the "uniformity of coating thickness" in 3 A sign "O" is given when the actual measurement T is the coating thickness of the resin coating layer 3 falls within the range of t - 2σ ≦ T ≦ t + 2σ and indicates a sign "X" when the actual measured value T is out of the above range.

As in 3 11, the coefficient of friction stabilization time in the first to thirteenth embodiment examples (A-1 to A-13) is relatively short (2.3 hours on the average), and moreover, the final friction coefficient is relatively low (0.00035 on the average). In contrast, the comparative examples include even an example (the fourth comparative example B-4) in which the friction coefficient is not stabilized. Even in the other comparative examples where the friction coefficient is stabilized, the friction coefficient stabilizing time is relatively long (on average, 4.7 hours) and the final friction coefficient is relatively high (0.00063 on the average). Therefore, it is shown that the configuration of the present invention, in which the average Coating thickness t of the resin coating layer 3 falls within the range described above and the ratio of the reduced peak height Rpk to the average coating thickness t falls within the other range described above, the conformability of the sliding bearing 10 improves and reduces the friction coefficient.

Further, in the first to fifth embodiment examples (A-1 to A-5) among the first to thirteenth embodiment examples (A-1 to A-13), the average coating thickness t of the resin coating layer 3 in a range of 2.0 μm to 4.5 μm (2.0 μm ≤ t ≤ 4.5 μm) and the ratio of the reduced peak height Rpk of the resin coating layer 3 to the average coating thickness t is in a range of 0.1 to 2.0 (0.1 ≦ Rpk / t ≦ 2.0). The average friction coefficient stabilizing time in the first to fifth embodiment examples (A-1 to A-5) is 1.2 hours, and the average value of the final friction coefficient in the first to fifth embodiment examples (A-1 to A-5) is 0.00028. Thus, the results in the first to fifth embodiment examples (A-1 to A-5) are better than the average values in the first to thirteenth embodiment examples (A-1 to A-13).

The influence of the other parameters is also studied in the sixth to thirteenth embodiment examples (A-6 to A-13) in which it is considered that the influence of the average coating thickness t of the resin coating layer 3 and the influence of the ratio of the reduced peak height Rpk to the average coating thickness t are relatively similar. For example, in the sixth to eleventh embodiment examples (A-6 to A-11), the difference in distances measured between the protrusion regions is an index of the approximation between the incision and supernatant shape of the inner peripheral surface of the bearing alloy layer 2 and the incision and supernatant shape of the resin coating layer 3 equal to or less than 0.05 mm (| Rsma - Rsmr | ≤ 0.05 mm). In the same embodiment examples, the distance Δ measured in the axial direction between the protrusion portions is on the inner peripheral surface of the bearing alloy layer 2 and the nearest protrusion areas of the resin coating layer 3 , equal to or less than one-third of the distance Rsma of the supernatant portions of the bearing alloy layer 2 (Δ ≤ Rsma / 3). The sixth to eleventh embodiment examples (A-6 to A-11) each have, on average, a relatively short friction coefficient stabilizing time as compared with the twelfth and thirteenth embodiment examples (A-12, A-13) in which the difference in distances and Distance Δ are different from the above value ranges. The average value of the friction coefficient stabilizing time in the sixth to eleventh embodiment examples (A-6 to A-11) is 2.8 hours, while the average value of the friction coefficient stabilizing time in the twelfth and thirteenth embodiment examples (A-12, A-13) is 3.8 Hours. The sixth to eleventh embodiment examples (A-6 to A-11) have, on average, a relatively low final friction coefficient as compared with the twelfth and thirteenth embodiment examples (A-12, A-13). The average value of the final friction coefficient in the sixth to eleventh embodiment examples (A-6 to A-11) is 0.00038, while the average value of the final friction coefficient in the twelfth and thirteenth embodiment examples (A-12, A-13) is 0, Is 00040.

As above, it is confirmed that the time required to complete the conformity is shortened when the bearing alloy layer 2 and the resin coating layer 3 are formed such that each parameter falls within the respective range defined in the present invention. In addition, in the first to thirteenth embodiment examples (A-1 to A-13), it is confirmed that the friction coefficient is successfully reduced.

4 FIG. 10 illustrates a profile of the temporal variation of the friction coefficient during the initial conformity in an embodiment example and a comparative example. FIG. The solid line I denotes the change in the embodiment example and the solid line II denotes the change in the comparative example. Here, the embodiment example indicates a case where the average coating thickness t, the reduced peak height Rpk / t ratio Rpk to the average coating thickness t, and the conditions of the approximation between the incision and supernatant shape of the inner peripheral surface of the bearing alloy layer 2 and the incision and supernatant shape of the resin coating layer 3 all within the ranges defined in the present invention. For example, in the embodiment example, the following conditions are satisfied: 1.0 μm ≤ t ≤ 5.0 μm; 0.06 ≤ R pk / t ≤ 5.04; t - 2σ ≤ T ≤ t + 2σ; | Rsma - Rsmr | ≤ 0.05 mm and Δ ≤ Rsma / 3. In contrast, the comparative example designates another case in which, of the above conditions, at least one of "1.0 μm ≦ t ≦ 5.0 μm" and "0.06 ≦ Rpk / t ≦ 5.04" is not satisfied. As indicated by an arrow a in 4 is shown, the embodiment example completes the conformity in a shorter period of time than the comparative example. In addition, as indicated by an arrow b in 4 shown, understood that the resulting coefficient of friction after completing the conformity in the Embodiment example is less than that in the comparative example. 4 shows the advantageous effect of the present invention that the conformity is improved and the friction coefficient is successfully reduced.

The bearing alloy layer 2 is made of an aluminum alloy in the above embodiment. Alternatively, the bearing alloy layer 2 made of a copper alloy or a tin alloy having a Vickers hardness equal to or greater than 30.

To the resin coating layer 3 Particles can be added such. Calcium phosphate, magnesium phosphate, barium phosphate, lithium phosphate, tribasic lithium phosphate, tribasic calcium phosphate, calcium hydrogenphosphate, magnesium hydrogenphosphate, lithium pyrophosphate, calcium pyrophosphate, magnesium pyrophosphate, lithium metaphosphate, calcium metaphosphate, magnesium metaphosphate, lithium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, calcium sulfate, barium sulfate, barium carbonate, titanium oxide, iron ( III) oxide, carbon fluoride, ultrahigh molecular weight polyethylene, sericite and stannic sulfide.

As a pretreatment before the formation of the resin coating layer 3 , the bearing alloy layer 2 are processed by surface-roughening treatment by blasting, surface-modification treatment by alkali and the like, ultra-fine incision and supernatant treatment by chemical etching, chemical conversion treatment, primer treatment, corona discharge treatment or the like.

The method of forming the resin coating layer 3 is not limited to spray coating but may be roller coating.

In the case that the inner peripheral surface of the plain bearing 10 Alternatively, an oil groove formed so as to extend in the circumferential direction or in the axial direction may alternatively have a resin coating layer formed inside the oil groove.

The present invention is not limited to the above description of each aspect and the embodiment. The present invention includes various modifications provided that the modifications are within the scope of the claims and that those skilled in the art readily remember. The entire content, which is clearly described in the present specification, such as. For example, published patent applications are incorporated herein by reference.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2004-211859 A [0002]
• JP 2011-179566 A [0004]

Cited non-patent literature

• JIS B0671-2 [0031]
• ISO 13565-2: 1996 [0031]

Claims (5)

Sliding bearing for an internal combustion engine, characterized by: a metal layer ( 2 ) having an inner peripheral surface formed to extend along at least a portion of a cylindrical shape; and a resin coating layer ( 3 ) formed on the inner peripheral surface of the metal layer (FIG. 2 ), wherein: the inner peripheral surface of the metal layer ( 2 ) has annular or spiral groove portions extending in a generally circumferential direction of the cylindrical shape so that the inner peripheral surface has protrusion portions disposed adjacent to each other in the axial direction of the cylindrical shape and in the generally revolving direction extend; the resin coating layer ( 3 ) to conform to shapes of the groove areas and the overhang areas; and t and Rpk satisfy the following relationships: 1.0 μm ≤ t ≤ 5.0 μm and 0.06 ≤ Rpk / t ≤ 5.04, where t is the average coating thickness of the resin coating layer ( 3 ) at positions other than the peaks of the protrusion regions; and Rpk a reduced peak height of the resin coating layer (FIG. 3 ). The sliding bearing according to claim 1, wherein: the average coating thickness t and the reduced peak height Rpk of the resin coating layer (FIG. 3 ) satisfy the following relationships: 2.0 μm ≤ t ≤ 4.5 μm and 0.1 ≤ Rpk / t ≤ 2.0. A sliding bearing according to claim 1 or 2, wherein: T, t and σ satisfy the following relationship: t - 2σ ≦ T ≦ t + 2σ, where σ is the standard deviation of the coating thicknesses of the resin coating layer (FIG. 3 ), measured at the positions other than the peaks of the protrusion regions, and T is an actual measurement of the coating thickness; Rsma and Rsmr satisfy the following relation: | Rsma - Rsmr | ≤ 0.05 mm, wherein Rsma has an average length measured between the adjacent protrusion areas on the inner peripheral surface of the metal layer (FIG. 2 ), and Rsmr is an average length measured between corresponding adjacent protrusion portions of the resin coating layer (FIG. 3 ), is, according to the supernatant regions of the metal layer ( 2 ); and Rsma and Δ satisfy the following relationship: Δ ≤ Rsma / 3, where Δ is a distance, measured in the axial direction, between one of the protrusion regions on the inner peripheral surface of the metal layer (FIG. 2 ) and a corresponding one of the protrusion portions of the resin coating layer (FIG. 3 ), with the one corresponding area being positioned closest to the one of the protrusion areas of the metal layer (FIG. 2 ). A sliding bearing according to any one of claims 1 to 3, wherein: the resin coating layer ( 3 ) has a scratch resistance in the range of 500 MPa to 2000 MPa. A sliding bearing according to any one of claims 1 to 4, wherein: the resin coating layer (10) 3 ) contains a base resin and a solid lubricant; the base resin contains polyamide-imide and polyamide corresponding to 2 to 20% of the polyamide-imide by volume; the solid lubricant contains one or more of molybdenum disulfide, tungsten disulfide, boron nitride and graphite; and the solid lubricant total 20 to 60% of the entirety of the resin coating layer ( 3 ), based on the volume corresponds.

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